Amorphous Co-doped MoS2 nanosheet coated metallic CoS2 nanocubes as an excellent electrocatalyst for hydrogen evolution

An amorphous Co-doped MoS2 coated highly crystalline pyrite-phase CoS2 hierarchical nanoarray exhibits ultrahigh activity towards acidic hydrogen evolution with a low onset potential (similar to 44 mV) and a small overpotential of similar to 110.5 mV for driving the current density of similar to 10 mA cm(-2), ascribed to its novel hierarchical structure and the Co doping caused synergistic effects.